noIncrementDecrement

JavaScript (and super languages)

Caution

此规则是 nursery 组的一部分。这意味着此功能处于实验阶段，其行为可能随时更改。

¥This rule is part of the nursery group. This means that it is experimental and the behavior can change at any time.

摘要

¥Summary

• 规则生效日期：v2.3.2

  ¥Rule available since: v2.3.2

• 诊断类别：lint/nursery/noIncrementDecrement

  ¥Diagnostic Category: lint/nursery/noIncrementDecrement

• 此规则没有修复方案。

  ¥This rule doesn’t have a fix.

• 此规则的默认严重级别为 information。

  ¥The default severity of this rule is information.

• 来源：

  ¥Sources:

  • 与 no-plusplus 相同

    ¥Same as no-plusplus

如何配置

¥How to configure

biome.json

{
  "linter": {
    "rules": {
      "nursery": {
        "noIncrementDecrement": "error"
      }
    }
  }
}

描述

¥Description

禁止使用一元运算符 ++ 和 —。

¥Disallows the usage of the unary operators ++ and —.

由于一元 ++ 和 — 运算符会自动插入分号，因此空格的差异可能会改变源代码的语义。

¥Because the unary ++ and — operators are subject to automatic semicolon insertion, differences in whitespace can change semantics of source code.

let i = 10;
let j = 20;

i ++
j
// i = 11, j = 20

code-block.js:4:1 lint/nursery/noIncrementDecrement ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Unexpected use of increment/decrement unary operator.
  
    2 │ let j = 20;
    3 │ 
  > 4 │ i ++
      │ ^^^^
    5 │ j
    6 │ // i = 11, j = 20
  
  ℹ The unary ++ and — operators are subject to automatic semicolon insertion, differences in whitespace can change semantics of source code. Instead use += or -=.
  

let i = 10;
let j = 20;

i
++
j
// i = 10, j = 21

code-block.js:5:1 lint/nursery/noIncrementDecrement ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Unexpected use of increment/decrement unary operator.
  
    4 │ i
  > 5 │ ++
      │ ^^
  > 6 │ j
      │ ^
    7 │ // i = 10, j = 21
    8 │ 
  
  ℹ The unary ++ and — operators are subject to automatic semicolon insertion, differences in whitespace can change semantics of source code. Instead use += or -=.
  

示例

¥Examples

无效

¥Invalid

let foo = 0;
foo++;

code-block.js:2:1 lint/nursery/noIncrementDecrement ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Unexpected use of increment/decrement unary operator.
  
    1 │ let foo = 0;
  > 2 │ foo++;
      │ ^^^^^
    3 │ 
  
  ℹ The unary ++ and — operators are subject to automatic semicolon insertion, differences in whitespace can change semantics of source code. Instead use += or -=.
  

let bar = 42;
bar--;

code-block.js:2:1 lint/nursery/noIncrementDecrement ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Unexpected use of increment/decrement unary operator.
  
    1 │ let bar = 42;
  > 2 │ bar—;
      │ ^^^^^
    3 │ 
  
  ℹ The unary ++ and — operators are subject to automatic semicolon insertion, differences in whitespace can change semantics of source code. Instead use += or -=.
  

for (let i = 0; i < 10; i++) {
    doSomething(i);
}

code-block.js:1:25 lint/nursery/noIncrementDecrement ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Unexpected use of increment/decrement unary operator.
  
  > 1 │ for (let i = 0; i < 10; i++) {
      │                         ^^^
    2 │     doSomething(i);
    3 │ }
  
  ℹ The unary ++ and — operators are subject to automatic semicolon insertion, differences in whitespace can change semantics of source code. Instead use += or -=.
  

for (let i = 0; i < 10;) {
    doSomething(i);
    i++;
}

code-block.js:3:5 lint/nursery/noIncrementDecrement ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Unexpected use of increment/decrement unary operator.
  
    1 │ for (let i = 0; i < 10;) {
    2 │     doSomething(i);
  > 3 │     i++;
      │     ^^^
    4 │ }
    5 │ 
  
  ℹ The unary ++ and — operators are subject to automatic semicolon insertion, differences in whitespace can change semantics of source code. Instead use += or -=.
  

有效

¥Valid

let foo = 0;
foo += 1;

let bar = 42;
bar -= 1;

for (let i = 0; i < 10; i += 1) {
    doSomething(i);
}

for (let i = 0; i < 10;) {
    doSomething(i);
    i += 1;
}

选项

¥Options

allowForLoopAfterthoughts

允许在 for 循环的后置表达式（最终表达式）中使用一元运算符 ++ 和 —。

¥Allows unary operators ++ and — in the afterthought (final expression) of a for loop.

默认 false

¥Default false

biome.json

{
  "linter": {
    "rules": {
      "nursery": {
        "noIncrementDecrement": {
          "options": {
            "allowForLoopAfterthoughts": true
          }
        }
      }
    }
  }
}

无效

¥Invalid

for (let i = 0; i < j; j = i++) {
    doSomething(i, j);
}

code-block.js:1:28 lint/nursery/noIncrementDecrement ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Unexpected use of increment/decrement unary operator.
  
  > 1 │ for (let i = 0; i < j; j = i++) {
      │                            ^^^
    2 │     doSomething(i, j);
    3 │ }
  
  ℹ The unary ++ and — operators are subject to automatic semicolon insertion, differences in whitespace can change semantics of source code. Instead use += or -=.
  

for (let i = 10; i--;) {
    doSomething(i);
}

code-block.js:1:18 lint/nursery/noIncrementDecrement ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Unexpected use of increment/decrement unary operator.
  
  > 1 │ for (let i = 10; i—;) {
      │                  ^^^
    2 │     doSomething(i);
    3 │ }
  
  ℹ The unary ++ and — operators are subject to automatic semicolon insertion, differences in whitespace can change semantics of source code. Instead use += or -=.
  

for (let i = 0; i < 10;) i++;

code-block.js:1:26 lint/nursery/noIncrementDecrement ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Unexpected use of increment/decrement unary operator.
  
  > 1 │ for (let i = 0; i < 10;) i++;
      │                          ^^^
    2 │ 
  
  ℹ The unary ++ and — operators are subject to automatic semicolon insertion, differences in whitespace can change semantics of source code. Instead use += or -=.
  

有效

¥Valid

for (let i = 0; i < 10; i++) {
    doSomething(i);
}

for (let i = 0, j = l; i < l; i++, j--) {
    doSomething(i, j);
}

相关链接

¥Related links

• 禁用规则

  ¥Disable a rule

• 配置代码修复

  ¥Configure the code fix

• 规则选项

  ¥Rule options

• 源代码

  ¥Source Code

• 测试用例

  ¥Test Cases